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Yuan Q, Wang P, Wang X, Hu B, Tao L. Phytoremediation of cadmium-contaminated sediment using Hydrilla verticillata and Elodea canadensis harbor two same keystone rhizobacteria Pedosphaeraceae and Parasegetibacter. CHEMOSPHERE 2022; 286:131648. [PMID: 34315079 DOI: 10.1016/j.chemosphere.2021.131648] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/11/2021] [Accepted: 07/21/2021] [Indexed: 05/09/2023]
Abstract
Aquatic macrophytes have been widely employed for in-situ phytoremediation of cadmium (Cd) polluted sediments. But, little is known about the responses of rhizosphere bacteria and their interspecific interactions to phytoremediation. In this study, the α-diversity, community composition, co-occurrence network and keystone species of sediment bacteria in rhizosphere zones of two typical macrophytes, Hydrilla verticillata and Elodea canadensis, were investigated using 16S rRNA gene high-throughput sequencing. The results showed that after fifty days of phytoremediation, a group of specialized sediment bacteria were assembled in the rhizosphere zones closely associated with different host macrophytes. Rhizosphere micro-environments, i.e., the increases of redox potential and organic matter and the decreases of pH, nitrogen and phosphorus, reduced bacterial α-diversity through niche-based species-sorting process, which in turn reduced interspecific mutualistic relationships. But meanwhile, benefiting from the nutrients supplied from macrophyte roots, more bacterial species survived in the highly Cd-contaminated sediments (50 mg kg-1). In addition, the co-occurrence network revealed that both macrophytes harbored two same keystone bacteria with the high betweenness centrality values, including the family Pedosphaeraceae (genus_unclassified) and genus Parasegetibacter. Their relative abundances were up to 28-fold and 25-fold higher than other keystone species, respectively. Furthermore, these two keystone bacteria were metabolic generalists with vital ecological functions, which posed significant potentials for promoting plant growth and tolerating Cd bio-toxicity. Therefore, the identified keystone rhizobacteria, Pedosphaeraceae and Parasegetibacter, would be potential microbial modulations applied for the future optimization of phytoremediation in Cd-contaminated sediment.
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Affiliation(s)
- Qiusheng Yuan
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, Jiangsu, 210098, PR China.
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, Jiangsu, 210098, PR China.
| | - Xun Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, Jiangsu, 210098, PR China.
| | - Bin Hu
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, Jiangsu, 210098, PR China.
| | - Li Tao
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, Jiangsu, 210098, PR China.
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Javed MT, Saleem MH, Aslam S, Rehman M, Iqbal N, Begum R, Ali S, Alsahli AA, Alyemeni MN, Wijaya L. Elucidating silicon-mediated distinct morpho-physio-biochemical attributes and organic acid exudation patterns of cadmium stressed Ajwain (Trachyspermum ammi L.). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 157:23-37. [PMID: 33069978 DOI: 10.1016/j.plaphy.2020.10.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 10/08/2020] [Indexed: 05/11/2023]
Abstract
Soil contamination with toxic heavy metals [such as cadmium (Cd)] is becoming a serious global problem due to rapid development of social economy. Silicon (Si), being an important fertilizer element, has been found effective in enhancing plant tolerance against biotic and abiotic stresses. The present study investigated the extent to which different levels of Si modulated the Cd tolerance of Ajwain (Trachyspermum ammi L.) seedlings when maintained in artificially Cd spiked regimes. A pot experiment was conducted under controlled conditions for four weeks, by using sand, mixed with different levels of Cd i.e., 0, 1.5 and 3 mM together with the application of Si at 0, 1.5 and 3 mM levels to monitor different growth, gaseous exchange, oxidative stress, antioxidative responses, minerals accumulation, organic acid exudation patterns of T. ammi seedlings. Our results depicted that Cd addition to growth medium significantly decreased plant growth and biomass, gaseous exchange attributes and minerals uptake by T. ammi seedlings as compared to the plants grown without addition of Cd. However, Cd toxicity boosted the production of reactive oxygen species (ROS) by increasing the contents of malondialdehyde (MDA), which is the indication of oxidative stress in T. ammi seedlings and was also manifested by hydrogen peroxide (H2O2) contents and electrolyte leakage to the membrane bounded organelles. Although, activities of various antioxidative enzymes like superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) initially increased up to a Cd level of 1.5 mM but were significantly diminished at the highest Cd level of 3 mM. Results revealed that the anthocyanin and soluble proteins contents were decreased in seedlings grown under elevating Cd levels but increased the Cd accumulation of T. ammi roots and shoots. The negative impacts of Cd injury were reduced by the application of Si which increased plant growth and biomass, improved photosynthetic apparatus, antioxidant enzymes, minerals uptake together with diminished exudation of organic acids as well as oxidative stress indicators in roots and shoots of T. ammi by decreasing Cd retention in different plant parts. Research findings, therefore, suggested that Si application can ameliorate Cd toxicity in T. ammi seedlings and resulted in improved plant growth and composition under metal stress as depicted by balanced exudation of organic acids.
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Affiliation(s)
- Muhammad Tariq Javed
- Department of Botany, Government College University, Faisalabad, 38000, Pakistan
| | - Muhammad Hamzah Saleem
- MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Sidra Aslam
- Department of Bioinformatics and Biotechnology, Government College University Allama Iqbal Road, 38000, Faisalabad, Pakistan
| | - Muzammal Rehman
- School of Agriculture, Yunnan University, Kunming, 650504, China
| | - Naeem Iqbal
- Department of Botany, Government College University, Faisalabad, 38000, Pakistan
| | - Ruqiyya Begum
- Department of Botany, Government College University, Faisalabad, 38000, Pakistan
| | - Shafaqat Ali
- Department of Environmental Sciences and Engineering, Government College University Allama Iqbal Road, 38000, Faisalabad, Pakistan; Department of Biological Sciences and Technology, China Medical University, Taichung, 40402, Taiwan.
| | - Abdulaziz Abdullah Alsahli
- Department of Botany and Microbiology, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia
| | - Mohammed Nasser Alyemeni
- Department of Botany and Microbiology, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia
| | - Leonard Wijaya
- Department of Botany and Microbiology, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia
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Shahid M, Javed MT, Tanwir K, Akram MS, Tazeen SK, Saleem MH, Masood S, Mujtaba S, Chaudhary HJ. Plant growth-promoting Bacillus sp. strain SDA-4 confers Cd tolerance by physio-biochemical improvements, better nutrient acquisition and diminished Cd uptake in Spinacia oleracea L. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2020; 26:2417-2433. [PMID: 33424156 PMCID: PMC7772128 DOI: 10.1007/s12298-020-00900-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/15/2020] [Accepted: 10/17/2020] [Indexed: 05/29/2023]
Abstract
Cadmium (Cd) is highly toxic metal for plant metabolic processes even in low concentration due to its longer half-life and non-biodegradable nature. The current study was designed to assess the bioremediation potential of a Cd-tolerant phytobeneficial bacterial strain Bacillus sp. SDA-4, isolated, characterized and identified from Chakera wastewater reservoir, Faisalabad, Pakistan, together with spinach (as a test plant) under different Cd regimes. Spinach plants were grown with and without Bacillus sp. SDA-4 inoculation in pots filled with 0, 5 or 10 mg kg-1 CdCl2-spiked soil. Without Bacillus sp. SDA-4 inoculation, spinach plants exhibited reduction in biomass accumulation, antioxidative enzymes and nutrient retention. However, plants inoculated with Bacillus sp. SDA-4 revealed significantly augmented growth, biomass accumulation and efficiency of antioxidative machinery with concomitant reduction in proline and MDA contents under Cd stress. Furthermore, application of Bacillus sp. SDA-4 assisted the Cd-stressed plants to sustain optimal levels of essential nutrients (N, P, K, Ca and Mg). It was inferred that the characterized Cd-tolerant PGPR strain, Bacillus sp. SDA-4 has a potential to reduce Cd uptake and lipid peroxidation which in turn maintained the optimum balance of nutrients and augmented the growth of Cd-stressed spinach. Analysis of bioconcentration factor (BCF) and translocation factor (TF) revealed that Bacillus sp. SDA-4 inoculation with spinach sequestered Cd in rhizospheric zone. Research outcomes are important for understanding morpho-physio-biochemical attributes of spinach-Bacillus sp. SDA-4 synergy which might provide efficient strategies to decrease Cd retention in edible plants and/or bioremediation of Cd polluted soil colloids.
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Affiliation(s)
- Muhammad Shahid
- Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, 38000 Pakistan
| | | | - Kashif Tanwir
- Department of Botany, Government College University, Faisalabad, 38000 Pakistan
| | | | - Syeda Khola Tazeen
- Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, 38000 Pakistan
| | - Muhammad Hamzah Saleem
- MOA Key Laboratory of Crop Ecophysiology and Farming System Core in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Sajid Masood
- Soil and Water Testing Laboratory, Pakarab Fertilizer, Multan, 60000, Pakistan
| | - Sadia Mujtaba
- Department of Botany, Government College University, Faisalabad, 38000 Pakistan
| | - Hassan Javed Chaudhary
- Department of Plant Sciences, Faculty of Biological Sciences, Quaid-I-Azam University, Islamabad, 45320 Pakistan
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α-Tocopherol Foliar Spray and Translocation Mediates Growth, Photosynthetic Pigments, Nutrient Uptake, and Oxidative Defense in Maize (Zea mays L.) under Drought Stress. AGRONOMY-BASEL 2020. [DOI: 10.3390/agronomy10091235] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A pot experiment was conducted to assess the induction of drought tolerance in maize by foliar-applied α-tocopherol at early growth stage. Experiment was comprised two maize cultivars (Agaiti-2002 and EV-1098), two water stress levels (70% and 100% field capacity), and two α-tocopherol levels (0 mmol and 50 mmol) as foliar spray. Experiment was arranged in a completely randomized design in factorial arrangement with three replications of each treatment. α-tocopherol was applied foliary at the early vegetative stage. Water stress reduced the growth of maize plants with an increase in lipid peroxidation in both maize cultivars. Contents of non-enzymatic antioxidants and activities of antioxidant enzymes increased in studied plant parts under drought, while the nutrient uptake was decreased. Foliary-applied α-tocopherol improved the growth of both maize cultivars, associated with improvements in photosynthetic pigment, water relations, antioxidative mechanism, and better nutrient acquisition in root and shoot along with tocopherol contents and a decrease in lipid peroxidation. Furthermore, the increase of tocopherol levels in roots after α-Toc foliar application confers its basipetal translocation. In conclusion, the findings confer the role of foliar-applied α-tocopherol in the induction of drought tolerance of maize associated with tissue specific improvements in antioxidative defense mechanism through its translocation.
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Ponce SC, Prado C, Pagano E, Prado FE, Rosa M. Effect of pH on Cr(III) accumulation, biomass production, and phenolic profile in 2 Salvinia species. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2019; 38:167-176. [PMID: 30303559 DOI: 10.1002/etc.4296] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 08/07/2018] [Accepted: 10/08/2018] [Indexed: 06/08/2023]
Abstract
We analyzed the effect of pH on Cr(III) accumulation, biomass production, and phenolic profile of Salvinia rotundifolia and Salvinia minima plants grown in the presence of increasing concentrations of CrCl3 . Biomass accumulation, metal tolerance index, and photosynthetic pigment contents indicate that Salvinia rotundifolia seems to be more tolerant of Cr(III) than S. minima at different pHs. Increased metal accumulation by Salvinia species under increasing pH could be explained by changes of the protonation status of cell wall functional groups because both the highest and the lowest pH values used in the present study were outside of the levels at which Cr(III) species start to precipitate. The metal translocation factor indicates that in buffered conditions S. rotundifolia tend to retain more Cr(III) in lacinias than S. minima, probably through the involvement of insoluble phenolics. The results of the present study could be useful to the management of solution pH to maximize the removal of Cr(III) by aquatic plants. Environ Toxicol Chem 2019;38:167-176. © 2018 SETAC.
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Affiliation(s)
- Silvana Chocobar Ponce
- Instituto de Bioprospección y Fisiología Vegetal, CONICET-UNT, Cátedra de Fisiología Vegetal, Facultad de Ciencias Naturales e IML, Universidad Nacional de Tucumán, Tucumán, Argentina
| | - Carolina Prado
- Instituto de Bioprospección y Fisiología Vegetal, CONICET-UNT, Cátedra de Fisiología Vegetal, Facultad de Ciencias Naturales e IML, Universidad Nacional de Tucumán, Tucumán, Argentina
| | - Eduardo Pagano
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones en Biociencias Agrícolas y Ambientales, Facultad de Agronomía, Buenos Aires, Argentina
| | - Fernando E Prado
- Instituto de Bioprospección y Fisiología Vegetal, CONICET-UNT, Cátedra de Fisiología Vegetal, Facultad de Ciencias Naturales e IML, Universidad Nacional de Tucumán, Tucumán, Argentina
| | - Mariana Rosa
- Instituto de Bioprospección y Fisiología Vegetal, CONICET-UNT, Cátedra de Fisiología Vegetal, Facultad de Ciencias Naturales e IML, Universidad Nacional de Tucumán, Tucumán, Argentina
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Maleva M, Borisova G, Chukina N, Kumar A. Urea increased nickel and copper accumulation in the leaves of Egeria densa (Planch.) Casp. and Ceratophyllum demersum L. during short-term exposure. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 148:152-159. [PMID: 29040823 DOI: 10.1016/j.ecoenv.2017.10.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 10/02/2017] [Accepted: 10/04/2017] [Indexed: 06/07/2023]
Abstract
In the present study, two fresh water plant species Egeria densa (Planch.) Casp. and Ceratophyllum demersum L. were subjected to separate and combined action of urea (2mМ) and metals (Ni and Cu, 10μM) to investigate the phytoremediation potential of these two submerged macrophytes during short-term experiments (48h). Both submerged macrophytes demonstrated high accumulative potential for Ni and Cu (average bioconcentration factors were 2505 for Ni and 3778 for Cu). The urea (2 mM) was not significantly toxic for studied plant species. Futhermore, urea worked as an additional source of nitrogen and stimulated some metabolic processes such as the synthesis of photosynthetic pigments, soluble proteins, non-enzymatic antioxidants, and activated some enzymes. Adding urea to the metals increased their accumulation in both macrophytes (on average by 35% for Ni and 15% for Cu). Combined action of urea and Ni did not have a significant effect on antioxidant response, but caused a sharp increase of urease activity (4 folds on an average) in both plants. The copper exerted a stronger toxic effect on both studied macrophytes compared to nickel. Adding urea to copper in some cases diminished the toxic action of this metal. Study concludes that the responses of E. densa and C. demersum to urea and metal action (separate and combined) were depended on the type of pollutant and the activity of antioxidant defence system. Therefore, the studied aquatic macrophytes found to be potential phytoremediators of water bodies, the addition of an organic nitrogen source in the form of urea in environmentally relevant concentration will increase the efficiency of phytoextraction of metals.
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Affiliation(s)
- Maria Maleva
- Department of Experimental Biology and Biotechnology, Institute of Natural Sciences and Mathematics, Ural Federal University, Mira str., 19, Ekaterinburg 620002, Russia
| | - Galina Borisova
- Department of Experimental Biology and Biotechnology, Institute of Natural Sciences and Mathematics, Ural Federal University, Mira str., 19, Ekaterinburg 620002, Russia
| | - Nadezhda Chukina
- Department of Experimental Biology and Biotechnology, Institute of Natural Sciences and Mathematics, Ural Federal University, Mira str., 19, Ekaterinburg 620002, Russia
| | - Adarsh Kumar
- Department of Experimental Biology and Biotechnology, Institute of Natural Sciences and Mathematics, Ural Federal University, Mira str., 19, Ekaterinburg 620002, Russia.
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He Y, Rui H, Chen C, Chen Y, Shen Z. The role of roots in the accumulation and removal of cadmium by the aquatic plant Hydrilla verticillata. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:13308-13316. [PMID: 27023818 DOI: 10.1007/s11356-016-6505-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 03/17/2016] [Indexed: 06/05/2023]
Abstract
Aquatic macrophytes can absorb heavy metals either from sediments via the root system, from the water phase by leaves, or from both sources. In this study, cadmium accumulation and distribution in the aquatic plant Hydrilla verticillata were investigated, with a focus on the role of roots. Results showed that leaves of H. verticillata had a higher Cd concentration than roots when intact plants were grown in sediments and solutions containing Cd. Cadmium can significantly decrease the leaf chlorophyll content, and the leaves of intact plants with roots had lower chlorophyll contents than the leaves of detached ones without roots due to the transfer effect of roots. The majority of the Cd accumulated in leaves of H. verticillata was bound to the cell walls. When roots were submerged in a solution containing Cd, with shoots in a control solution without Cd, the Cd concentrations in leaves were considerably lower than in roots. In contrast, Cd was almost undetectable in roots when the shoots were submerged in a solution containing Cd, with roots in the control solution. Compared to the leaves and stems of detached shoots without roots, the concentrations of Cd were much higher in the leaves and stems of intact plants with roots. It is suggested that the roots of intact plants absorb Cd and transfer it to leaves and that more Cd is removed from the solution by intact plants.
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Affiliation(s)
- Yan He
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Haiyun Rui
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
- Taizhou University, Taizhou, 225300, People's Republic of China
| | - Chen Chen
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Yahua Chen
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Zhenguo Shen
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
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Maleva M, Borisova G, Chukina N, Prasad MNV. Urea-induced oxidative damage in Elodea densa leaves. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:13556-13563. [PMID: 25943514 DOI: 10.1007/s11356-015-4600-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 04/23/2015] [Indexed: 06/04/2023]
Abstract
Urea being a fertilizer is expected to be less toxic to plants. However, it was found that urea at 100 mg L(-1) caused the oxidative stress in Elodea leaves due to the formation of reactive oxygen species (ROS) and lipid peroxidation that are known to stimulate antioxidant pathway. Urea at a concentration of 500 and 1000 mg L(-1) decreased low-molecular-weight antioxidants. In this case, the antioxidant status of plants was supported by the activity of antioxidant enzymes such as superoxide dismutase and guaiacol peroxidase. A significant increase in the soluble proteins and -SH groups was observed with high concentrations of urea (30-60 % of control). Thus, the increased activity of antioxidant enzymes, low-molecular-weight antioxidants, and induced soluble protein thiols are implicated in plant resistance to oxidative stress imposed by urea. We found that guaiacol peroxidase plays an important role in the removal of the peroxide in Elodea leaves exposed to 1000 mg L(-1)of urea.
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Affiliation(s)
- Maria Maleva
- Department of Plant Physiology and Biochemistry, Faculty of Biology, Institute of Natural Sciences, Ural Federal University named after the first President of Russia B.N. Yeltsin, Lenin av., 51, Ekaterinburg, 620000, Russia,
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Azeem M, Iqbal N, Kausar S, Javed MT, Akram MS, Sajid MA. Efficacy of silicon priming and fertigation to modulate seedling's vigor and ion homeostasis of wheat (Triticum aestivum L.) under saline environment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:14367-71. [PMID: 26154041 DOI: 10.1007/s11356-015-4983-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 06/29/2015] [Indexed: 05/06/2023]
Abstract
Seed preconditioning, a short gun approach to modulate the effects of abiotic stresses on crop plants, has recently gained considerable attention of the researchers to induce salinity tolerance in agronomically important crops. The present study was conducted to explore the comparative efficacy of presowing seed priming with silicon (Si) and Si fertigation to modulate the wheat growth and ion dynamics. Seeds of wheat variety, PUNJAB-11, were sown in Petri plates having nutrient solutions with (120 mM) and without NaCl. Six levels of Si (0, 10, 20, 30, 40, or 50 mM), applied as sodium silicate (Na2SiO3), were tested either as a seed priming agent or as a supplement in the nutrient solution. Priming of seeds with Si mitigated the adverse effects of salinity stress on germination percentage, root as well as shoot length, dry and fresh weight. Application of Si either as preconditioning of seeds or addition in the growth medium resulted in reduced accumulation of sodium (Na(+)) in wheat seedlings under saline environment. Seedling's potassium (K(+)) contents either remained unaffected or decreased whereas calcium (Ca(2+)) contents decreased at all Si concentrations except at 30 mM when Si primed seeds were grown under salt stress. Addition of Si, under salt stress, in cultivation medium exerted a positive effect on seedling's K(+) and Ca(2+) contents. Silicon contribution to decontamination strategies was evaluated.
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Affiliation(s)
- Muhammad Azeem
- Department of Botany, Governement College University, Faisalabad, 38000, Pakistan
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Javed MT, Lindberg S, Greger M. Cadmium uptake in Elodea canadensis leaves and its interference with extra- and intra-cellular pH. PLANT BIOLOGY (STUTTGART, GERMANY) 2014; 16:615-621. [PMID: 24016297 DOI: 10.1111/plb.12086] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 07/03/2013] [Indexed: 06/02/2023]
Abstract
This study investigated cadmium (Cd) uptake in Elodea canadensis shoots under different photosynthetic conditions, and its effects on internal (cytosolic) and external pH. The plants were grown under photosynthetic (light) or non-photosynthetic (dark or in the presence of a photosynthetic inhibitor) conditions in the presence or absence of CdCl2 (0.5 μm) in a medium with a starting pH of 5.0. The pH-sensitive dye BCECF-AM was used to monitor cytosolic pH changes in the leaves. Cadmium uptake in protoplasts and leaves was detected with a Cd-specific fluorescent dye, Leadmium Green AM, and with atomic absorption spectrophotometry. During cultivation for 3 days without Cd, shoots of E. canadensis increased the pH of the surrounding water, irrespective of the photosynthetic conditions. This medium alkalisation was higher in the presence of CdCl2 . Moreover, the presence of Cd also increased the cation exchange capacity of the shoots. The total Cd uptake by E. canadensis shoots was independent of photosynthetic conditions. Protoplasts from plants exposed to 0.5 μm CdCl2 for 3 days did not exhibit significant change in cytosolic [Cd(2+)] or pH. However, exposure to CdCl2 for 7 days resulted in increased cytosolic [Cd(2+) ] as well as pH. The results suggest that E. canadensis subjected to a low CdCl2 concentration initially sequesters Cd into the apoplasm, but under prolonged exposure, Cd is transported into the cytosol and subsequently alters cytosolic pH. In contrast, addition of 10-50 μm CdCl2 directly to protoplasts resulted in immediate uptake of Cd into the cytosol.
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Affiliation(s)
- M T Javed
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden; Department of Botany, Government College University, Faisalabad, Pakistan
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Tariq Javed M, Lindberg S, Greger M. Cellular proton dynamics in Elodea canadensis leaves induced by cadmium. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 77:15-22. [PMID: 24525352 DOI: 10.1016/j.plaphy.2014.01.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 01/18/2014] [Indexed: 06/03/2023]
Abstract
Our earlier investigations showed that Elodea canadensis shoots, grown in the presence of cadmium (Cd), caused basification of the surrounding medium. The present study was aimed to examine the proton dynamics of the apoplastic, cytosolic and vacuolar regions of E. canadensis leaves upon Cd exposure and to establish possible linkage between cellular pH changes and the medium basification. The changes in cytosolic calcium [Ca(2+)]cyt was also investigated as the [Ca(2+)]cyt and [pH]cyt homeostasis are closely linked. The cellular H(+) and Ca(2+) concentrations were monitored by fluorescence microscopy and ion-specific fluorescent dyes. Cadmium concentration of leaf-cell walls was measured after plant cultivation at different fixed levels of starting pH. The protoplasts from E. canadensis leaves were isolated by use of a newly developed enzymatic method. Upon Cd addition, both cytosolic and vacuolar pH of leaf protoplasts increased with a concomitant rise in the cytosolic Ca(2+) concentration. Time course studies revealed that changes in [Ca(2+)]cyt and [pH]cyt followed similar dynamics. Cadmium (0.5 μM) exposure decreased the apoplastic pH by 0.85 units. The maximum cell wall bound Cd-contents were obtained in plants grown at low starting pH. It is concluded that Cd treatment causes apoplastic acidosis in E. canadensis leaves associated with enhanced Cd binding to the cell walls and, consequently, reduced Cd influx into the cytosol.
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Affiliation(s)
- M Tariq Javed
- Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-10691 Stockholm, Sweden.
| | - Sylvia Lindberg
- Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-10691 Stockholm, Sweden
| | - Maria Greger
- Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-10691 Stockholm, Sweden
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Jacob DL, Borchardt JD, Navaratnam L, Otte ML, Bezbaruah AN. Uptake and translocation of Ti from nanoparticles in crops and wetland plants. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2013; 15:142-53. [PMID: 23487992 DOI: 10.1080/15226514.2012.683209] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Bioavailability of engineered metal nanoparticles affects uptake in plants, impacts on ecosystems, and phytoremediation. We studied uptake and translocation of Ti in plants when the main source of this metal was TiO2 nanoparticles. Two crops (Phaseolus vulgaris (bean) and Triticum aestivum (wheat)), a wetland species (Rumex crispus, curly dock), and the floating aquatic plant (Elodea canadensis, Canadian waterweed), were grown in nutrient solutions with TiO2 nanoparticles (0, 6, 18 mmol Ti L(-1) for P. vulgaris, T. aestivum, and R. crispus; and 0 and 12 mmol Ti L(-1) for E. canadensis). Also examined in E. canadensis was the influence of TiO2 nanoparticles upon the uptake of Fe, Mn, and Mg, and the influence of P on Ti uptake. For the rooted plants, exposure to TiO2 nanoparticles did not affect biomass production, but significantly increased root Ti sorption and uptake. R. crispus showed translocation of Ti into the shoots. E. canadensis also showed significant uptake of Ti, P in the nutrient solution significantly decreased Ti uptake, and the uptake patterns of Mn and Mg were altered. Ti from nano-Ti was bioavailable to plants, thus showing the potential for cycling in ecosystems and for phytoremediation, particularly where water is the main carrier.
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Affiliation(s)
- Donna L Jacob
- Wet Ecosystem Research Group, Department of Biological Sciences, North Dakota State University, Dept. 2715, PO Box 6050, Fargo, ND 58108-6050, USA.
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